Why Can't i see my desktop background?

I got this Asus laptop, its vista and i used to be able to change the desktop background easily.

But suddenly, the next day, i switched on my laptop and realised that the background was pitch black with not wallpaper.

I am able to change the background colour but i am just unable to set a wallpaper.

When i went to control panels to change the wallpaper, i am able to select the picutures but i cant see it.

 In other words, I cant see the pictures available for us to choose for our wallpaper but i am able to select it.

 But when i jus randomly select the pic, the background is still pitch black.

And that 'cant see picture prob' oso happened to the rest of my pictures in my folders.

i am able to see my pics in the folders onli when i refreshed the page about 3 times.

When i searched for pictures on the internet, i right click on the picutre and slelect 'set as background wallpaper' and it works!

But i still hav no idea why my laptop has this prob. Help pls?